Antisense nucleic acids for the prevention and treatment of disorders in which expression of c-erbB plays a role

ABSTRACT

The present invention is related to an antisense-nucleic acid or effective derivatives thereof hybridizing with an area of the messenger RNA (mRNA) or the DNA, encoding the p185 erbB-2  receptor (also termed c-erbB-2, HER2 or neu), a pharmaceutical composition, comprising an antisense nucleic acid or effective derivatives thereof hybridizing with an area of the messenger RNA (mRNA) or the DNA, encoding the c-erbB-2 receptor as well as the use of said antisense nucleic acids and derivatives thereof for the manufacturing of a pharmaceutical composition for the treatment of neoplasms and/or immune diseases and/or diseases involving pathological angiogenesis.

The present invention is related to an antisense-nucleic acid or effective derivatives thereof hybridizing with an area of the messenger RNA (mRNA) or the DNA, encoding the p185^(erbB-2) receptor (also termed c-erbB-2, HER2 or neu), a pharmaceutical composition, comprising an antisense nucleic acid or effective derivatives thereof hybridizing with an area of the messenger RNA (mRNA) or the DNA, encoding the c-erbB-2 receptor as well as the use of said antisense nucleic acids and derivatives thereof for the manufacturing of a pharmaceutical composition for the treatment of neoplasms and/or immune diseases and/or diseases involving pathological angiogenesis.

ErbB-2 is a putative growth factor receptor with an intracellular tyrosine kinase activity that is amplified and/or overexpressed by tumor cells in a variety of neoplasms including breast cancer, lung cancer, esophageal and gastric cancer, bile duct carcinoma, bladder cancer and ovarian cancer.

In breast carcinoma patients, an amplification and overexpression of the c-erbB-2 gene in the tumor tissue has been shown to correlate with a poor clinical prognosis. Overexpression of p185^(erbB-2) in non-small-cell lung carcinoma has been shown to impart resistance to a number of chemotherapeutic agents.

WO 93/09788 discloses a method for inhibiting the proliferation of cells which contain an erb B2/neu gene site. The method involves administering a therapeutic dose of an oligonucleotide which is capable of forming a colinear triplex with the promoter region of the erb B2/neu gene.

WO 92/19732 discloses sense and antisense oligonucleotides, namely closed oligonucleotides. These compounds may be used pharmacologically as sense or antisense molecules. It is generally described the therapeutic use of oligonucleotides as sense or antisense agents.

WO 92/13063 discloses a method for effecting expression of growth factors and growth factor receptors in cells or in multicellular animals and methods for testing compounds as effectors of transcription of growth factors and growth factor receptors.

The article “Chemically Modified Oligodeoxynucleotide Analogs as Regulators of Viral and Cellular Gene Expression” in Gene Regulation: Biology of Antisense RNA and DNA discloses in general the use of chemically modified oligonucleotides in the antisense technology.

It is an object of the present invention to provide a compound for the treatment of neoplasms and/or immune diseases and/or diseases involving pathological angiogenesis.

The c-erbB-2 antisense-oligonucleotide of the invention solving the problem addressed above have the sequences as disclosed in the sequence listing under Seq. ID No. 1-105, having a DNA- or RNA-type structure. The control oligonucleotide has the sequence as disclosed in the sequence listing under Seq. ID No 106, having a DNA- or RNA-type structure.

The antisense nucleic acids of the invention, were able to strongly inhibit the expression of the p185^(erbB-2) protein, tyrosine kinase activity and cell growth in a variety of tumor cells including breast cancer cells. Untransformed normal fibroblasts were not growth inhibited by the anti-c-erbB-2 antisense compounds. This suggests that p185^(erbB-2) plays a pathogenetic role in the growth of the above mentioned tumor cells.

Furthermore, surprisingly, the immune response to a variety of neoplasms was significantly increased by the use of the antisense nucleic acids of the invention. Immune cell growth and activity was stimulated in co-culture assays culturing tumor cells and peripheral blood monocytes together.

Surprisingly, the antisense nucleic acids of the invention, also acted as strong inhibitors of angiogenesis. This suggests, that either the secreted truncated form of the c-erbB-2 protein or the full receptor protein may play a causal role in pathological neoangiogenesis.

According to the invention antisense nucleic acids or effective derivatives thereof which hybridize with an area of the mRNA or DNA coding for p185^(erbB-2) can effectively treat the diseases addressed above. The antisense nucleic acid is able to hybridize with regions of p185^(erbB-2) mRNA. It is understood by the skilled person that fragments of the antisense nucleic acids and antisense nucleic acids containing these sequences work according to the invention so long as production of p185^(erbB-2) is reduced or inhibited.

According to the invention the antisense-oligonucleotides are obtainable by solid phase synthesis using phosphite triester chemistry by growing the nucleotide chain in 3′-5′ direction in that the respective nucleotide is coupled to the first nucleotide which is covalently attached to the solid phase comprising the steps of

cleaving 5′ DMT protecting group of the previous nucleotide,

adding the respective nucleotide for chain propagation,

modifying the phosphite group subsequently cap unreacted 5′-hydroxyl groups and

cleaving the oligonucleotide from the solid support,

followed by working up the synthesis product.

The chemical structures of oligodeoxy-ribonucleotides are given in FIG. 1 as well as the respective structures of antisense oligo-ribonucleotides are given in FIG. 2. The oligonucleotide chain is to be understood as a detail out of a longer nucleotide chain.

In FIG. 1, lit. B means an organic base such as adenine (A), guanine (G), cytosine (C) and thymine (T) which are coupled via N9(A,G) or N1(D,T) to the desoxyribose. The sequence of the bases is the reverse complement of the genetic target sequence (mRNA-sequence). The modifications used are

1. Oligodeoxy-ribonucleotides where all R¹ are substituted by

1.1 R¹=O

1.2 R¹=S

1.3 R¹=F

1.4 R¹=CH₃

1.5 R¹=OEt

2. Oligodeoxy-ribonucleotides where R¹ is varied at the internucleotide phosphates within one oligonucleotide

where

B=deoxy-ribonucleotide dA, dC, dG or dT depending on gene sequence

p=internucleotide phosphate

n=an oligodeoxy-ribonucleotide stretch of length 6-20 bases

2.1 R^(1a) = S; R^(1b) = O 2.2 R^(1a) = CH₃; R^(1b) = O 2.3 R^(1a) = S; R^(1b) = CH₃ 2.4 R^(1a) = CH₃; R^(1b) = S

3. Oligodeoxy-ribonucleotides where R¹ is alternated at the internucleotide phosphates within one oligonucleotide

where B=deoxy-ribonucleotide dA, dC, dG or dT depending on gene sequence

p=internucleotide phosphate

n=an oligodeoxy-ribodinucleotide stretch of length 4-12 dinucleotides

3.2 R^(1a) = S; R^(1b) = O 3.2 R^(1a) = CH₃; R^(1b) = O 3.3 R^(1a) = S; R^(1b) = CH₃

4. Any of the compounds 1.1-1.5; 2.1-2.4; 3.1-3.3 coupled at R² with the following compounds which are covalently coupled to increased cellular uptake

4.1 cholesterol

4.2 poly(L)lysine

4.3 transferrin

5. Any of the compounds 1.1-1.5; 2.1-2.4; 3.1-3.3 coupled at R³ with the following compounds which are covalently coupled to increase cellular uptake

5.1 cholesterol

5.2 poly(L)lysine

5.3 transferrin

In the case of the RNA-oligonucleotides (FIG. 2) are the basis (adenine (A), guanine (G), cytosine (C), uracil (U)) coupled via N9 (A,G) or N1 (C,U) to the ribose. The sequence of the basis is the reverse complement of the genetic target sequence (mRNA-sequence). The modifications in the oligonucleotide sequence used are as follows

6. Oligo-ribonucleotides where all R¹ are substituted by

6.1 R¹=O

6.2 R¹=S

6.3 R¹=F

6.4 R¹=CH₃

6.5 R¹=OEt

7. Oligo-ribonucleotides where R¹ is varied at the internucleotide phosphates within one oligonucleotide

where

B=ribonucleotide A, C, G or T depending on gene sequence

p=internucleotide phosphate

n=an oligo-ribonucleotide stretch of length 4-20 bases

7.1 R^(1a) = S; R^(1b) = O 7.2 R^(1a) = CH₃; R^(1b) = O 7.3 R^(1a) = S; R^(1b) = CH₃ 7.4 R^(1a) = CH₃; R^(1b) = S

8. Oligo-ribonucleotides where R¹ is alternated at the internucleotide phosphates within one oligonucleotide

where

B=ribonucleotide A, C, G or T depending on gene sequence

p=internucleotide phosphate

n=an oligo-ribodinucleotide stretch of length 4-12 dinucleotides

8.2 R^(1a) = S; R^(1b) = O 8.3 R^(1a) = CH₃; R^(1b) = O 8.4 R^(1a) = S; R^(1b) = CH₃

9. Any of the compounds 6.1-6.5; 7.1-7.4; 8.1-3.3 coupled at R² with the following compounds which are covalently coupled to increase cellular uptake

9.1 cholesterol

9.2 poly(L)lysine

9.3 transferrin

10. Any of the compounds 6.1-6.5; 7.1-7.4; 8.1-8.3 coupled at R³ the following compounds are covalently coupled to increased cellular uptake

10.1 cholesterol

10.2 poly (L) lysine

10.3 transferrin

11. Any of the compounds 6.1-6.5; 7.1-7.4; 8.1-8.3; 9.1-9.3; 10.1-10.3 where all R⁴ are substituted by

11.1 R⁴=O

11.2 R⁴=F

11.3 R⁴=CH₃

In a preferred embodiment of the oligonucleotides of the invention they are phosphorothioate derivatives, having a DNA- or RNA-type structure.

It is possible that one single individual sequence as mentioned above works as an antisense nucleic acid or oligonucleotide structure according to the invention. However, it is also possible that one strand of nucleotides comprises more than one of the sequences as mentioned above directly covalently linked or with other nucleotides covalently linked in between. Preferably, individual oligonucleotides are addressed.

In a preferred embodiment of these oligo-nucleotides they are phosphorothioate derivatives.

Modifications of the antisense-oligonucleotides are advantageous since they are not as fast destroyed by endogenous factors when applied as this is valid for naturally occurring nucleotide sequences. However, it is understood by the skilled person that also naturally occurring nucleotides having the disclosed sequence can be used according to the invention. In a very preferred embodiment the modification is a phosphorothioate modification.

The synthesis of the oligodeoxy-nucleotide of the invention is described as an example in a greater detail as follows.

Oligodeoxy-nucleotides were synthesized by stepwise 5′-addition of protected nucleosides using phosphite triester chemistry. The nucleotide A was introduced as 5′dimethoxytrityl-deoxyadenosine(N-benzoyl)-N,N′-diisopropyl-2-cyano-ethyl phosphoramidite (0.1 M); C was introduced by a 5′-dimethoxytrityl-deoxycytidine (N⁴-benzoyl)-N,N′-diisopropyl-2-cyanoethyl phosphoramidite; G was introduced as 5′-dimethoxytrityl-deoxyguanosine(N⁸-isobutyryl)-N,N′-diisopropyl-2-cyanoethyl phosphoramidite and the T was introduced as 5′-dimethoxytrityl-deoxythymidine-N,N′-diisopropyl-2-cyanoethyl phosphoramidite. The nucleosides were preferably applied in 0.1 M concentration dissolved in acetonitrile.

Synthesis was performed on controlled pore glass particles of approximately 150 μm diameter (pore diameter 500 Å) to which the most 3′ nucleoside is covalently attached via a long-chain alkylamine linker (average loading 30 μmol/g solid support).

The solid support was loaded into a cylindrical synthesis column, capped on both ends with filters which permit adequate flow of reagents but hold back the solid synthesis support. Reagents were delivered and withdrawn from the synthesis column using positive pressure of inert gas. The nucleotides were added to the growing oligonucleotide chain in 3′->5′ direction. Each nucleotide was coupled using one round of the following synthesis cycle:

Cleave 5′DMT (dimethoxytrityl) protecting group of the previous nucleotide with 3-chloroacetic acid in dichloromethane followed by washing the column with anhydrous acetonitrile.

Then simultaneously one of the bases in form of their protected derivative depending on the sequence was added plus tetrazole in acetonitrile. After reaction the reaction mixture has been withdrawn and the phosphite was oxidized with a mixture of sulfur (S₈) in carbon disulfide/pyridine/triethylamine. After the oxidation reaction the mixture was withdrawn and the column was washed with acetonitrile. The unreacted 5′-hydroxyl groups were capped with simultaneous addition of 1-methylimidazole and acetic anhydride/lutidine/tetrahydrofuran. Thereafter, the synthesis column was washed with acetonitrile and the next cycle was started.

The work up procedure and purification of the synthesis products occurred as follows.

After the addition of the last nucleotide the deoxynucleotides were cleaved from the solid support by incubation in ammonia solution. Exocyclic base protecting groups were removed by further incubation in ammonia. Then the ammonia was evaporated under vacuum. Full-length synthesis products still bearing the 5′DMT protecting group were separated from shorter failure contaminants using reverse phase high performance liquid chromatography on silica C₁₈ stationary phase. Eluents from the product peak were collected, dried under vacuum and the 5′-DMT protecting group cleaved by incubation in acetic acid which was evaporated thereafter under vacuum. The synthesis products were solubilized in the deionized water and extracted three times with diethylether. Then the products were dried in vacuo. Another HPLC-AX chromatography was performed and the eluents from the product peak were dialyzed against excess of Trisbuffer as well as a second dialysis against deionized water. The final products were lyophilized and stored dry.

The antisense-nucleic acid of the invention can be used as pharmaceutical composition or medicament. This medicament can be used for treating neoplasms and/or immune diseases and/or diseases involving pathological angiogenesis in which the expression of c-erbB-2 derived receptor protein or truncated p185^(c-erbB2) is of relevance for the pathogenicity. It can be used to reduce neoplastic cell growth in cells expressing p185^(c-erbB2), to reverse resistance of tumor cells to the immune-response, to inhibit pathological angiogenesis and to stimulate the immune system.

The antisense nucleic acids of the invention are intermediate products of the pharmaceutical composition or medicament of the invention. The pharmaceutical composition may comprise besides the effective compound(s) suitable carrier agents, solvents and other ingredients known in the art for producing medicaments. Preferably, these agents facilitate the administration of the pharmaceutical composition of the invention. Typically, the pharmaceutical composition is administered as i.v. infusion or i.v. bolus injection. The amount of the active ingredient to be administered is typically in the range of 0.2-50 mg of the oligonucleotide per kg body weight per day, in particular 1-12 mg/kg body weight per day.

In principal the compound which can be used as an active compound in the pharmaceutical composition can be used as a diagnostic tool for evaluating whether the respective genes are expressed. Typically, radio active labelled nucleotides are hybridized by the method of northern blotting which is well-known in the art or in situ with a sample to be examined. The degree of hybridization is a measure for the degree of expression of the respective genes.

The effect of c-erbB2 specific antisense-oligonucleotides on neoplastic cell growth was investigated. It was demonstrated that antisense oligodeoxynucleotides as well as phosphorothioate modified nucleic acids, complementary to c-erbB2 mRNA could specifically inhibit p185^(c-erbB2) protein expression and could to a significant amount reduce cell proliferation in breast cancer cells, ovarian carcinoma cells and bladder cancer cells. Also, it could be shown that protein synthesis and S6 kinase activity were strongly reduced in tumor cells, treated with the antisense nucleic acid.

Furthermore, the immune response to a variety of neoplasms was significantly increased by the use of the antisense nucleic acids described below. Lymphocyte growth and activity was stimulated in co-culture assays culturing tumor cells and peripheral blood monocytes together.

Furthermore, the antisense nucleic acids described above, also acted as inhibitors of angiogenesis. 

What is claimed is:
 1. An antisense oligonucleotide, which will hybridize with an area of the messenger RNA (mRNA) and/or DNA encoding c-erbB-2, selected from the group consisting of SEQ. ID NOS. 1-105, wherein said antisense oligonucleotide has a DNA- or RNA-type structure.
 2. The antisense oligonucleotide of claim 1 wherein the oligonucleotides are modified as phosphorothioate derivatives.
 3. A method of making an antisense oligonucleotide according to claim 1 obtained by solid phase synthesis using phosphite triester chemistry by growing the nucleotide chain in 3′-5′ direction, in that the respective nucleotide is coupled to the first nucleotide which is covalently attached to the solid phase, comprising the steps of cleaving 5′ DMT protecting group of the previous nucleotide, adding the respective nucleotide for chain propagation, modifying phosphite groups, subsequently capping unreacted 5′-hydroxyl groups, and cleaving the oligonucleotide from the solid support, followed by working up the synthesis product.
 4. A method for inhibiting expression of c-erbB-2 in cells or in cells in culture comprising delivering the antisense oligonucleotide of claim 1 to said cells such that it inhibits c-erbB-2 expression.
 5. A method of assaying for c-erbB-2 gene expression comprising the steps of: radioactive labeling of the antisense oligonucleotide of claim 1 and combining a radioactive labeled nucleic acid with a sample, whereby, the degree of hybridization of the radioactive labeled oligonucleotide is a measure of the degree of expression of the gene encoding c-erbB-2. 